Determination of tin by electrothermal atomic absorption spectrometry with a tungsten-coated tube

Abstract

The W-coated tube was prepared, without soaking in the tungstate solution, and applied to the determination of tin in a fish sample. The coating process involved simply injecting 100 µl of a sodium tungstate solution (0.01 mol l^–1) into a graphite tube [pyrolytic graphite (PG) and non-pyrolytic graphite (NPG) tubes], followed by heating according to a temperature programme similar to an atomization cycle for the determination of tin. This procedure for coating was repeated five times and the coated surface gave high stable signals for at least 100 firings. The W-coated NPG tube gave the highest and most stable absorption signal for tin in a sea bass sample.